A Complete System for Vehicle License Plate Recognition

Abstract

This work proposes a system for automatic recognition of vehicle license plate. Three phases are involved in the process: image acquisition, plate recognition and postprocessing. New algorithms for the second phase are described herein. The system first locates the plate in the image, and then it segments the characters of the plate and recognizes them. An algorithm based on vertical edge detection and color alternation in grayscale image, is proposed to locate the plate. To segment the characters, a thresholding algorithm based on Fuzzy logic and a region growth algorithm are used. Two Multi-Layer Perceptron neural networks are used to recognize the characters. The results achieved by each of these steps were over 85% of correctness, what shows the robustness of the proposed algorithms, making them suitable for real world applications.